Method of making attaching members



Oct. 23, 1934. G, JQHNSON 1,978,088

METHOD OF MAKING ATTAGHING MEMBERS Original Filed July 15, 1932 F191. Ilag- 4.

Patented I Oct. 23, 1934 METHOD or MAKING: ATTACHING i MEMBERS GustavJohnson, West Roxbury, Mass, assignor to United-Carr FastenerCorporation, Cambridge, Mass., a corporation of Massachusetts l Original(application .July 15, 1932, Serial No.

622,605.- Divided and this application Decem- -ber 7,1932, Serial No.646,125

' 3 Claims. (01. 1027) 1 My invention aims to provide improvements inthe method-of making attaching members for use in attaching buttons,snap fastener elements and the like to their carrying mediums.

5 -This is a division of my co-pending application Serial No. 622,605,filed July 15, 19321 In the drawing, which illustrates a preferredembodiment of my invention:

Figures 1 through each show a plan and 10 a cross-section of a blankshowing the successive steps of forming my device froma flat disk to acomplete sharp pointed, reinforced shank; Fig. 1-1 is a sectional viewshowing portions of dies and an attaching member in cross-section l5 andillustrating the manner of compressing the shank'from the formationshown in Fig. 8 to. the

formation shown in Fig. 9;

Fig. 12 is a viewsimilar to that shown in Fig. 11, but showing otherdies for compressing the 2'0 shank from the formation shown inFig. 9 tothe ginning of the operation of the dies;

Fig. 13 is a section of the part shown in Fig. 12 but showing-thecompleted operation of the formation shown in Fig. 10 and shows the be-25dies and the increased thickness of the shank of sheet metal andhaving a base 1 from which is pressed a shank 2 having a sharp point 3.The tack may be made by passing a piece of suitable metal beneath aseries of dies in a stepby-step manner, as will be understood by anyoneskilled in the art from an inspection of the figures of the drawing Theattaching member,

as well as the method of forming it after the opening in the end of theshank is closed, is an improvement over that shown in the application.45 to Gustav Johnson, Serial No. 430,366, filed February 21, 1930, andthe divisional of that application, Serial No. 494,031, filed March 7,1930.

As pointed out in the applications referred to above, the first steps ofmaking my improved device are obvious to those skilled in the art andthe improvements covered by those applications relate to the idea ofcutting away a portion of the blunt end of the shank 2, as shown in Fig.7, and thereafter pointing the apertured blunt end.

That important feature was accomplished by compressing the tack shank 2,as shown in Fig.

'7, between a pair of male and female dies, thereby closing the aperture4 and forming the sharp tapered point 3 (Fig. 8) having a substantiallysmooth continuous surface. The removal of a portion of the blunt end wasfor the purpose of permitting the remaining portion to be easily formedinto a sharp pointed non-wrinkled portion of'substantial length whichcould be readily upset for riveting purposes. 1

I have found that an improved attaching member may be made by providingthe shank of the attaching member with a wall which is of greaterthickness adjacent to the base 1 than adjacent to the'free end.Therefore, my invention as disclosed by the annexeddrawing is for animproved rivet or tack having a portion of the shank made thicker andthe method of accomplishing the desired result. By increasing thethickness of the wall of 'the shank for a portionof its'length adjacentto the base, that portion of the shank including the pointed portionabove the thickened portion may be more easily upset and much moreneatly riveted." Also by strengthening the lower end portion of theshank there is an assurance that the shank will be riveted properlywithout any substantial distortion ofthat portion of the shank whichpasses through the carrying medium. .5 (Fig. 14) and the portion 6 ofthe part 7 to be attached. In other words,'the upper end of the shank isbound to be distorted laterally and substantially symmetrically duringthe riveting oper ation and no telescoping of the bottom portion cantake place since besides the wall being thickened there is substantiallyno space surrounded by the wall.

Referring now to the particular method of forming my improved rivet ortack after the blunt end of the blank A (Fig. 6) has been cut away (Fig.7) and then pressed between dies to form a sharp pointed end, as shownin Fig. 9, the steps are as follows. The blank B, Fig. 8, is placedbetween opposed dies 8 and 9 (Fig. 11) which are moved toward each otherin any suitable manner. The die 8 is provided with a bored cylinder fora portion of its length and tapered to a point throughout the remainderof its length. The diameter of the cylindrical portion is such that thewall 10 surrounding it will pass over the greater portion of the pointedportion 3 before engaging the shank 2 of the tack, as clearlyillustrated in Fig. 11. Therefore, when the dies are moved together theshank of the attaching member below the sharp pointed portion is reducedto a smaller diameter, as shown in Fig. 9, without to any great extent11 disturbing the contour of the tapered end and without, to any extent,changing the length of the completed shank over that shown in Fig. 11.The next blank C (Fig. 9) is placed between dies 11 and 12 (Fig. 12)which further reduces the shank 2. The die member 11 has a bore 13 whichis similar to the one formed in the die 8 except that it is smaller indiameter and the wall 14 surrounding the bore 13 passes oversubstantially all of the pointed portion 3 of the shank before engagingthe shank in the same manner as described inconnection with the previousstep. During both of these operations just described, the shank belowthe pointed portion is reduced in diameterKFigs. 9 and 10) without, toany great degree, lengthening the shank. Therefore, the wall of theshank below the pointed portion and near the base is thickened by themetal being compressed. It should be understood that, while I have showntwo operations for accomplishing the desired thickening or the shank,any number of operations may be used and any suitable method employedwhile coming within the scope of my improved construction.

The advantage of my improved method is in the fact that I can form ashank of an attaching element which is stronger than that described anddisclosed in my application previously referred to while accomplishingthe desired result by a meth od which is impossible by step by step useof male and female dies. Therefore during the formation of the devicebeginning with the blank which is shown in Fig. 5, I provide a shankwhich is thicker in that portion nearest the base than that portion atthe end. This result is accomplished in the first one or more steps bydrawing out the end of the shank during the lengthening process. Duringthat part of the process which takes place after the shank has beenpointed, and as illustrated inFigs. 9 through 12, the shank diameterdecreases and thus substantially closes the shank adjacent to the baseas shown in Fig. 10. During these steps in the process no male die canbe entered into the shank nor is one necessary to accomplish the desiredresult.

My improved fastener member provides a self 'piercing tack-like devicewhich is simple in construction, inexpensive to manufacture. I It isadapted to be used very efficiently as a rivet in an automatic attachingmachine, since it finds its own way into proper engagement with a partto be attached and may be easily and efliciently riveted, because of therelatively weak point as compared to the strengthened shank especiallyadjacent to the base.

While I have illustrated and described a preferred embodiment of myinvention, I do not wish to be limited thereby, because the scope of myinvention is best defined by the following claims.

I claim:

1. The method of forming an attaching member in the form of a tackhaving a base, a shank and a sharp point on the end of the shank, whichcomprises pressing a hollow, blunt and shank from a sheet metal blank,cutting away a portion of the blunt end of the shank, forming theremainder of the material of said shank adjacent to the cut end into asharp point and thereafter compressing the shank to increase thethickness for a portion thereof adjacent to the base only.

2. The method of forming a sheet metal tack having a base, a shank and asharp point on the end of the shank, which comprises pressing a hol-'-low substantially rounded end shank from a sheet metal blank, cuttingaway a portion of the shank adjacent to the rounded end, pressing therounded end of the shank into a suitable die by longitudinal approachingmovement of one toward the."

close it adjacent to the base thereby increasing llo the strength of theshank portion below the pointed portion without to any extent changingthe length of the shank after pointing.

3. The method of forming an attaching member of the class describedhaving a base and apfla shank, which comprises pressing a hollow shankfrom a sheet metal blank and thereafter reducing the diameter of theshank adjacent to the base only by forcing it into a female die therebysubstantially to close the shank adjacent to thebase to strengthen itnear the base only.

GUSTAV JOHNSON.

